Implementing Google search operators

Question

Google currently uses keywords such as site: or is: in searches (the second example is from Gmail). I\'m trying to develop a similar system and am

Answer 1

Basics

sample string:

foo:(hello world) bar:(-{bad things}) email:something@email.tld another:weird characters +=2{-52!%#^ final:end

split with regex:

/\s+(?=\w+:)/

return array:

[
  'foo:(hello world)',
  'bar:(-{bad things})',
  'email:something@email.tld',
  'another:weird characters +=2{-52!%#^',
  'final:end'
]

regex explanation:

\s+     one or more spaces
(?=     followed by (positive lookahead)
  \w+   one or more word characters
  :     literal `:' (colon character)
)

usage:

Iterate through the array, split each element at : (colon). The left side key could be used to call a function and the right side value could be passed as the function parameter. This should pretty much put you on track for whatever you want to do from here.

Example ruby usage

search.rb

# Search class
class Search

  def initialize(query)
    @query = query
  end

  def foo(input)
    "foo has #{input}"
  end

  def bar(input)
    "bar has #{input}"
  end

  def email(input)
    "email has #{input}"
  end

  def another(input)
    "another has #{input}"
  end

  def final(input)
    "final has #{input}"
  end

  def exec
    @query.split(/\s+(?=\w+:)/).each do |e|
      method, arg = e.split(/:/)
      puts send(method, arg) if respond_to? method
    end
  end

end

use search.rb

q = "foo:(hello world) bar:(-{bad things}) email:something@email.tld another:weird characters +=2{-52!%#^ final:end";
s = Search.new(q)
s.exec

output

foo has (hello world)
bar has (-{bad things})
email has something@email.tld
another has weird characters +=2{-52!%#^
final has end